AVS 56th International Symposium & Exhibition
    Inkjet Technology: Printing, Materials Processing, and Microfluidics Fundamentals Topical Conference Wednesday Sessions
       Session IJ+MN+TF-WeA

Paper IJ+MN+TF-WeA11
Droplet Velocity Fluctuations in Thermally Stimulated Continuous Liquid Jets: Assessing the Effects of Nozzle Bore Geometry

Wednesday, November 11, 2009, 5:20 pm, Room B3

Session: Inkjet Printing Technology: Advances and Challenges
Presenter: J.M. Grace, Eastman Kodak Company
Authors: J.M. Grace, Eastman Kodak Company
G. Farruggia, Eastman Kodak Company
Correspondent: Click to Email
The break-up of thin liquid jets into droplets, known and studied for over a century, has significant practical applications, including inkjet printing. Whether jets are stimulated in on-demand or continuous modes, noise in the stimulation and break-up process can generate fluctuations in drop velocity. As inkjet technology continues to advance to higher resolution and the requirements for control of drop placement become increasingly more stringent, the fundamental noise characteristics of the break-up process become of increasing interest. In this presentation, we study the spatial jitter of drops to infer the underlying velocity fluctuations in thermally stimulated continuous fluid microjets. We present measurements of jitter for fluids jetted from nozzles having different bore radii and bore lengths. The jitter appears to decrease for decreasing nozzle bore lengths. Analysis based upon observed break-off lengths and the implied initial radial perturbations of the jet is presented as a means to assess whether nozzle bore geometry has a fundamental effect on jitter. In addition, analysis based upon energy delivered to the jet during each drop formation period is presented to assess the importance of thermal coupling between heater and jet.